Grinding machine for finishing crankshafts



April 6, 1966 F. L. MESSIER 3,247,618

GRINDING MACHINE FOR FINISHING CRANKSHAFTS Filed Nov. 18, 1963 5 Sheets-Sheet 1 INVENTOR l5 L.ME$SIEE April 26, 1966 F. L. MESSIER GRINDING MACHINE FOR FINISHING CRANKSHAFTS 3 Sheets-Sheet 2 Filed Nov. 18, 1963 5% & m g WM v 0 F m A ril 26, 1966 F. MESSIER 3,247,618

GRINDING MACHINE FOR FINISHING CRANKSHAFTS Filed Nov. 18, 1965 I5 Sheets-Sheet 5 INVENTOR fiA NC /5 L. MESS/EB L A TTOENEY United States Patent chusetts Filed Nov. 18, 1963, Ser. No. 324,549 10 Claims. (Cl. 51-5) This invention relates to grinding machines and more especially to machines designed to finish crankshafts.

It is customary in the manufacture of some types of crankshaits or similar work pieces to finish the end shoulders or side walls and to undercut the surfaces of the main and pin bearings adjacent the side walls of the bearing journals to form flanking grooves. The operation is now performed with a grinding wheel, the peripheral surface of which is profiled to grind the bearing surface, the shoulders and the flanking grooves at the same time. Such wheels, however, wear rapidly and require frequent truing, considerable care, and skill in use to produce a suitable blend between the bearing surface, side walls, and the flanking grooves which will not weaken the crankshaft and is acceptable to the customer.

The principal objects of this invention are therefore to provide apparatus for grinding the bearing surface and for finish cutting the shoulders and the flanking grooves independently of the grinding operation so as to minimize wheel wear and eliminate special wheel profiling, but at substantially the same time on the same machine, so that no time is lost; to provide an apparatus which is at least semi-automatic in that it will perform the finishing operations in succession; to provide an apparatus in which chatter and work deflection is minimized; to provide an apparatus which may be used in conjunction with.

a conventional grinding machine for the purpose of finishing crankshafts, but which may be removed therefrom when the grinding machine is required for other purposes; and to provide an apparatus which is of comparatively simple design and adjustable for crankshafts of different sizes. Another object is to .provide an apparatus which is useful for finishing work other than crankshafts.

As herein illustrated, the machine has a base mounting a work support and a grinding wheel for rotation of the work and the grinding wheel about spaced parallel, horizontally disposed axes and for movement of the grinding wheel toward the work to bring the wheel into engagement therewith, a tool, means mounting the tool on the base below the work for movement independently of the grinding wheel from a position at the wheel side of the work toward the far side thereof along a path parallel to a line tangent to the diameter to be ground, means for rotating the work, means for effecting movement of the tool to feed it into the work, and means for thereafter effecting movement of the grinding wheel to feed it into the work.

The means for mounting the tool is a slide movable along ways secured to the base and the tool is adjustable thereon at right angles to the direction of movement of the slide so that the tool may be adjusted radially relative to the axis of the work. There are work steadying elements on the slide movable therewith, arranged to have contact with the surface of the work while the grinding wheel is engaged with the work. One of the steadying elements is adapted to have contact with the wheel side of the work and is fixed relative to the slide and the other is adapted to have contact with the far side of the work, and there is means for retracting it to permit retraction of the slide and tool following a cutting operation with out interference with the work.

There is means connected to the base operable by movement of the slide as the tool is fed into the work to move 3,247,618 Patented Apr. 26, 1966 the retracted element supported by the slide into engagement with the work at substantially the same time that the relatively fixed element is moved with the slide into engagement with the work. Both elements include portions adjustable radially of the work.

The tool is a skiver-and has cutting edges constituted by laterally spaced projecting teeth which are offset in the direction of movement to undercut the surface of the bearing and finish cutting one of adjacent wallsof the bearing journal before or about the time the tool starts cutting the other side wall of the same journal. However, it is to be understood that for other kinds of work a different skiving tool may be employed.

There is a fluid operated motor for effecting movement of the tool slide and the motor and tool slide together with the tool and steadying rests are assembled as a unit for attachment to and removal from the work table of a conventional grinding machine. There is also means for controlling the rotation of the work, movement, of the tool slide and feeding movement of the rotating grinding wheel to effect their operation in the proper sequence.

The invention will now be described in greater retail with reference to the accompanying drawings wherein:

FIG. 1 is a fragmentary elevation partly in section of a grinding machine equipped to finish crankshafts according to this invention;

FIG. 2 is an enlarged vertical section of the crankshaft skiving tool and means for effecting its movement;

FIG. 3 is a plan view looking vertically down on FIG. 2; i

FIG. 4 is a vertical section through a crankshaft hearing showing the path of movement of the skiving tool in relation to the rotation of the crankshaft;

FIG. 5 is an elevation of the crankshaft as seen from the lefthand side of FIG. 4, with the skiving tool in section;

FIG. 6 is a detail View from the underside of the crankshaft showing the position of the skiving tool after having cut one shoulder and about to undercut the adjacent bearing surface; and

FIG. 7 is a hydraulic electric diagram of the control for the machine.

Referring to the drawings, and particularly to FIG. 1, the machine has a base 10 mounting a grinding wheel 12 and grinding wheel slide 14 for movement at right angles to a work supporting table 16, which in turn is supported on the base 10 by flat and V-shaped ways 18 and 20, for movement transversely of the machine. The grinding wheel 12 is fixed to a shaft 21 which has on it a pulley 22. A motor M1 is mounted on the slide adjacent the wheel and belts 24, entrained about the pulley 2.2 and-about a pulley 26 fixed to the shaft 28 of the motor M1, provide means for rotating the wheel.

At the underside of the wheel slide there is a boss 30 to which there is fixed a nut 32. The nut is threaded on a lead screw 34, one end of which is journaled for rotation in a cylindrical sleeve 36 supported for longitudinal movement in a cylinder 38 and the opposite end of which has an unthreaded extension 40 keyed slidably in the rear end of a sleeve bearing 42. The cylindrical sleeve 36 has at its rear end a rod 43 which extends into the cylinder 44 of a fluid motor and has on it a piston 46. By admitting oil to the right-hand end of the cylinder 44 as seen in FIG. 1, the piston may be advanced toward the left and, by such movement, advance the screw 34 bodily toward the left, for the purpose of rapidly feeding the grinding wheel toward the work mounted on the table 16.

Slow feed of the grinding wheel toward the work after it has been moved up to the work by the rapid feed means is effected by rotation of the screw 34 in conventional manner, as disclosed in the patent to Silven No. 2,572,529 issued October 21, 1951.

Briefly, a shaft 48 is splined at one end in the forward end of the sleeve bearing 42 and has secured to its other end a gear 50 which meshes with a driving gear 52 fixed to a shaft 54. The shaft 54 also supports a gear 56 rotatable on shaft 54, which meshes with a rack 58 formed on a piston 60, and is selectively coupled to gear 52 through a manually operated clutch as shown in FIG. 1. The piston 60 is movable longitudinally within a cylinder 62. By supplying fluid to the cylinder 62 the piston 60 may be moved in a direction to rotate the gear 50 and hence to rotate the screw 34. The gear 50 also meshes with a gear 64 integral with an index gear 68 rotatable on a fixed shaft 66. A hand wheel 70 is rotatably mounted on the shaft 66 and has on it a micrometer adjusting mechanism 72. There is a limit stop 74 fixed to the gear casing beside the hand wheel 70 and a cooperatinglimit stop 76 on the rim of the wheel, so that by rotating the hand wheel in a counter-clockwise direction or by supplying fluid to the left hand side of cylinder 62 as seen in FIG. 7, the screw 34 may be caused to turn through the aforesaid gears until the limit stops 74 and 76 are brought into engagement. Manual feeding may be effected by disengaging the clutch coupling the gear 52 to the gear 56 and rotating the hand Wheel. For a more specific description of the aforesaid control reference may be had to the patent identified above.

Work supports 2, only one of which is shown in FIG. 1, are mounted on the table 16 for supporting the work at a suitable level with reference to the grinding wheel for rotation about a horizontal axis parallel to the axis of the grinding wheel. The work supports 2, of which there may be two or more, are of the conventional type for holding work for rotation. A work drive motor M2. is mounted on the work support 2 shown in FIG. 1 for rotating the work in the conventional manner well known in the art.

A piston 78 enclosed by a cylinder 80 fixed to the underside of the table 16, functions by the application of hydraulic pressure to move the table transversely of the grinding wheel as shown in the aforesaid patent.

As previously mentioned, the purpose of this invention is to, form the undercut grooves at the ends of the main bearings and the pin bearings of a crankshaft adjacent the walls of the journals, without using a specially shaped grinding wheel for this purpose. This is accomplished herein by employing a simple cylindrical grinding wheel 12 with a transversely flat peripheral face for grinding the cylindrical surface of the bearing and a skiving tool 82 for cutting the grooves at the ends of the hearing. The skiving tool illustrated in FIGS. 2 through 7 has a cutting head, the forward face 84 of which, as shown in FIG. 5, has laterally spaced, forwardly projecting cutters 85-85 of half-circular shape, the cutters or teeth being offset so that the oneat the left side (FIG. 3) finish cuts before the one at the right side. The edge intermediate the forwardly projecting cutters 85-85 is spaced rearwardly of and below the leading edges of the cutters sufliciently so that the maximum required depth of the grooves may be made without contact of the intermediate edge with the cylindrical surface of the bearing. Preferably the tool 82 is formed in a hard block 86 set into the edge face of the tool block to improve its cutting action and to increase its resistance to wear.

The skiving tool 82 is adapted to engage the surface of the work, indicated at W in FIG. 2, and to be movable in a plane parallel to a line tangent to the diameter to be ground, with the projecting cutters 3585 traveling along lines tangent to the finished diameter of the work to be skived. To this end the tool is fastened by means of a bolt 88 to a rigid post 90. The post 90 is in turn fixedly secured to a tool slide 93 mounted on a rigid supporting member 92. The supporting member 92 is reniovably fastened to the inclined surface of a member 94 mounted on the table 16. A downwardly extending hook-like flange 96 at one edge of the member 94 and clamping blocks 98 secured against its opposite edge by bolts 1%, provide means for securing the supporting member 92 to the member 94, and thence through the table 16 to the base 10.

The tool slide 93 is mounted on a dovetail slide way 106 on the supporting member 92, as shown in FIGS. 2 and 3, and is connected at its left end as seen in FIG. 2 to one end of a piston rod 108, the opposite end of which extends into a cylinder 110 and has on it a piston 112. The cylinder 110 is integral with the supporting member 92 and by supplying fluid to the right end of cylinder 110 the piston 112 may be moved toward the left to move the attached tool slide 93 to the left and hence to ad vance the skiving tool 82 from an inoperative position at the wheel side of the work toward the work.

The skiving tool 82 is adjustable radially of the work by movement of the tool block along the slide way 114 on the face of the post 90. A rod 116 is fixed to the lower end ofthe tool block, with its lower end provided with a follower extending through a hole in the tool slide 93 into engagement with the inclined surface of a wedge 120 slidably disposed in an axial opening in the tool slide 93. The ends of the cylinder 110, the piston 112, piston rod 108 and tool slide 93 have axially aligned openings through which there is disposed a spindle 122, the inner end of which is threaded at 124 for engagement with the wedge 120. Axial movement of the spindle 122 relative to the tool slide 93 is prevented by means of a set screw 126 threaded through the piston rod into a groove 128 in the peripheral surface of the spindle. By rotation of the spindle with the bolt 88 loosened for this purpose the wedge may be moved either to raise or lower the skiving tool 82 hence to adjust the depth of the cut. A head 130 on the outer end of the spindle is graduated to indicate the amount of movement of the tool.

In the preferred form of the invention there are two work steadying elements 132a and 13212 associated with the tool slide 93 which are adapted to bear against the surface of the work to minimize chatter and deflection. The element 132]) is fixedly secured to tool post 90 and thence to the tool slide 93 so as to have contact with the underside of the work at the wheel side of the tool and the element 132a is pivotally mounted on the tool slide 93 for contact with the lateral surface of the work at the far side from the wheel.

The fixed element 132!) has a flat bearing surface 134 for tangential engagement with the surface of the work and is adjustably mounted in an opening 136 in the post 96 on a screw 138, so that by rotation of the screw its height-wise position with respect to the tool slide 93 may be adjusted. Set screws 140 and 142 provide for locking the element and screw in an adjusted position.

The pivotally supported element 1320, which also has a flat bearing surface, is similarly adjustably mounted at the upper end of an arm 144, the lower end of which is pivoted at 146 on the tool slide 93. A spring 148 is connected at one end to a pin 150 screwed into the arm 144 and at its other end to a pin 152 screwed into a boss 154 on the cylinder. The spring holds the arm against a spindle 156 adjustably threaded through the boss. As thus constructed, when the tool slide 93 moves to the left the arm is rocked clockwise as seen in FIGS. 2 and 7 on its lower end and when the slide is moved to the right the arm is rocked counterclockwise.

By adjustment of the spindle 156 the element 132:: may be caused to come into engagement with the surface of the work at the same time that the element 13% isv brought into engagement with the work and both elements.

are so adjusted that the engagement takes place at about the time that the grinding wheel moves into engagement with the surface of the work. As the diameter of the work is reduced the elements 132:; and 1321) are maintained in contact therewith by movement of the tool slide further to the left.

In the preferred form, the tool slide-93 and operating cylinder 110, including the tool 82 and steadying ele- 'ments 132a and 13% are assembled on the supporting member 92 so as to be removable as a unit from the table 16 of the machine. Optionally the table 16 may be omitted and the machine frame may be designed permanently to mount the tool slide and operating cylinder thus simplifying the structure to some extent where a table 16 is not required. Also, if desired, the work steadying elements 132a and 13% may be omitted and the work held in place solely by the work supports 2.

As previously pointed out, the cutting or skiving'tool82 is first brought into engagement with the surface of the work and following this the grinding wheel is brought into engagement with the surface of the work so that finishing of the grooves and the shoulders and finishing the bearing surface are effected one after another in close sequence.

Operation is semi-automatic, as will appear by reference to FIG. 7. As there shown, fluid pressure is provided by a motor driven pump P which delivers oil to the system under pressure from a reservoir 158 through a conductor C1, the latter being provided with a relief valve V through which oil may be returned to the reservoir through a conductor C2 in the event of excessive pressure within the system. Power is supplied to the pump motor M3 by closing the main switch SW1 connecting the machine to an outside source of power and by then closing the motor switch SW2. Switch SW3 is also closed to start the grinding wheel motor M1.

Operation of the machine is initiated by pressing a starting push button 160 which energizes coil CR1 so as to close switch 1CR. This permits flow of current to the solenoid S1 of a valve V1, shifting the spool in the valve V1 to the right. Oil then flows from the pump through the valve V1 and through line C3 to the righthand end of the tool slide cylinder 1119. Closing the switch lCR also energizes the motor M2 which initiates rotation of the work. Movement of the piston 112 to the left is first controlled by a regulator valve 162 for a skiving operation which finishes the side Walls and undercuts the bearing surface.

As the piston 112 approaches the dotted line position shown in FIG. 7 it actuates a normally open limit switch LS1. Limit switch LS1 energizes relay CR2 which closes switch 2CR and this in turn energizes solenoid S2 of valve V2 which shifts the spool in the valve V2 to the left. Movement of the spool to the left in valve V2 blocks the flow of oil from the cylinder 110, thus stopping the piston 112 in the position indicated in dotted lines with the skiving tool 82 in the finished position after engagement with the work and the steadying elements 132a and 1321: nearly but not quite touching the work. Closing switch 2CR also energizes coil TRl which closes switch lTR energizing the timer T1, closing the contacts LCl and RC1 which energizes solenoid S3 of a valve V3 so as to shift the spool therein in a direction to supply oil to the right end of the wheel slide cylinder 44 to advance the wheel slide. The contacts lTR of the relay TR1 open after a short time delay so that either switch 168 or the timer motor T1 is allowed to control the cycle.

The wheel slide 14 is advanced rapidly until the piston 46 covers the port near the left hand end of the cylinder 44 as seen in FIG. 7, whereupon it slows down and stops. Oil is also supplied to the cylinder 62 at the same time to advance the wheel slide at a slow speed by rotation of the screw 34. Toward the end of the slow speed feed a forwardly projecting finger 76a on the hand wheel actuates the normally open limit switch LS2 by engagement with the limit stop 74. Limit switch LS2 energizes coil CR3 which closes switch 3CR. Closing switch 30R energizes coil S4 of valve V4, shifting the spool to the left therein. This allows oiliat the left end of the tool slide cylinder 110 to exhaust through valve V4 so that the piston 112 resumes its stroke to the extreme left end of the cylinder 110 as seen in FIG. 2. Movement of the piston 11 2 is now controlled by the regulating valve 164 so that the work steadying elements 132:; and 132k are fed forward into engagement with the work to provide support as the grinding wheel finish grinds the cylindrical surface.

When the work has been finished to size the wheel slide will be retracted either manually by opening switch laser by the timer T1 energizing solenoid S3. Movement of the slide and hand wheel back to its initial position will release normally open limit switch LS2 deenergizing coil CR3 and solenoid 'S4 and open a normally closed one-Way switch LS3 breaking the holding circuit and deenergizing coil CR1, relay CR2 and relay TR'l and this in turn will stop the motor M2 and deenergize solenoids S1 and S2 to return the skiving tool to its initial position allowing normally open limit switch LS1 to open and relay TRl to reset. By opening a switch SW4 in the timer T1, the timer motor is made inoperative for manually retracting the wheel slide by opening the switch 168.

It should be understood that the foregoing disclosure is for the purpose of illustration only and that this invention includes all modifications and equivalents which fall within the scope of the appended claims.

I claim:

1. Apparatus for finishing crankshaft bearings and the like comprising first means for skiving a predetermined portion of a bearing, second means for grinding a. predetermined different portion of the same'bearing, and means effective first to operate said first means and then to operate said second means.

2. Apparatus for finishing crankshaft bearings comprising a skiving means including a first cutter mounted for feeding movement into engagement with a bearing to skive a first predetermined peripheral portion of a hearing and a second cutter mounted for feeding movement into engagement with the same bearing to skive a second predetermined peripheral portion of the same bearing spaced axial-1y of the bearing from the first peripheral portion thereof, grinding means mounted for feeding movement into engagement with the same bearing to grind a third predetermined peripheral portion of the same bearing between the first and the second peripheral portions thereof, first feeding means operable to produce feeding movement of said first and said second cutters,

second feeding means operable to produce feeding movement of said grinding means, and control means which operates first to actuate said first feeding means and then to actuate said second feeding means.

3. Apparatus for finishing crankshaft bearings and the like com-prising first means for skiving a first predetermined portion of a bearing, sec-0nd means for skiving a second predetermined portion of the same bearing, said first means and said second means being so arranged as to prevent the skiving of more than one of said first and said second predetermined portions of a bearing at a time, and means to grind a third predetermined portion of the same bearing.

4. Apparatus for finishing crankshaft bearings and adjacent shoulders or like work, comprising a base, a work support mounted on said base arranged to support a crankshaft or the like for rotation about the axis of one of the bearings to be finished, a grinding wheel, a grinding wheel support mounted upon said base and arranged to support said grinding wheel for rotation about its central axis and for movement into engagement with a crankshaft rotatably supported upon said work support, means for rotating a crankshaft so supported, means for rotating said grinding wheel, a skiving tool, means mounting said skiving tool on said base for feeding movement lengthwise of a line of action such that said skiving tool moves into and through predetermined portions of a crankshaft supported in said work support, said skiving tool having first and second cutters spaced both transversely and lengthwise relative to the direction of movement of said skiving tool, means operable to produce feeding movement of said skiving tool, and means operable after said skiving tool has been fed into and through predetermined portions of a crankshaft supported in said work support to produce feeding movement of the grinding wheel into engagement with the same crankshaft.

5. In an apparatus for finishing crankshaft bearings and adjacent shoulders or like work, including a base, a Work support mounted upon the base arranged to support a crankshaft for rotation about the axis of a bearing thereof to be finished, a grinding wheel, a grinding wheel support mounted upon the base and arranged to support the grinding wheel for rotation about a second axis parallel to the first axis and for movement into engagement with a bearing to be finished, means for rotating a crankshaft rotatably supported by the work support, means for rotating the grinding wheel, and means for feeding the grinding wheel toward a crankshaft supported on the work support; a skiving device comprising a skiving tool, means mounting said skiving tool on the base for feeding movement in a predetermined direction such that said skiving tool moves into and through a predetermined portion of -a crankshaft bearing to be finished, means for feeding said skiving tool, and control means operable first to actuate said means for feeding said skiving tool and then to actuate the means for feeding the grinding wheel.

6. Apparatus as described in claim wherein said skiving tool is provided with first and second cutters spaced both transversely and lengthwise relative to the direction of feeding movement of said skiving tool, said first and second cutters being positioned for movement chordwise of a crankshaft bearing to be finished.

7. Apparatus as described in claim 5 wherein said means mounting said skiving tool comprises an elongated slide movable in the direction of feeding movement for the skiving tool including a skiving tool support, and means mounted on said slide selectively operable to displace said skiving tool transversely of said slideto adjust the position of said skiving tool relative to a bearing to be finished.

8. Apparatus as described in claim 5, wherein said means mounting said skiving tool comprises a slide to which said skiving tool is fixedly secured movable in the direction of feeding movement of said skiving tool, and a pair of Work steadying elements mounted on said slide for movement therewith, said control means including means for effecting an initial movement of said slide to feed said skiving tool into and through a crankshaft hearing to be finished and to move said work steadying elements toward but not into contact with the s-unface of a bearing to be finished, and means operable when the means for feeding the grinding wheel is actuated for effecting additional movement of said slide to move said work steadying elements into operative engagement with the surface of a bearing to be finished.

9. In an apparatus for finishing crankshaft bearings and adjacent shoulders or like Work, including a base, a work support mounted upon the base arranged to support Work for rotation about a first axis coincident with the axis of rotation of a cylindrical portion thereof to be finished, a grinding wheel, a grinding wheel support mounted upon the base and arranged to support the grinding wheel for rotation about a second axis parallel to the first axis and for feeding movement into engagement with the portion to be finished of the work, means for rotating Work rotatably supported by the work support, means for rotating the grinding wheel, and means for producing feeding movement of the grinding wheel; a skiving device comprising a skiving tool, a tool slide supporting the skiving tool for sliding movement relative to the base, a pair of work steadying elements, one of said elements being fixedly secured to the tool slide adjacent the side of the work nearest the grinding wheel and the other of said elements being pivotally secured to the tool slide adjacent the side of the work most remote from the grinding wheel, spring means biasing the pivotally supported element into a retracted position, means fixed relative to the base arranged to engage the pivotally supported element during sliding movement of the tool slide so as to rotate the pivotally supported element toward the surface of the work, means for producing initial sliding movement of the tool slide to feed said skiving tool into and through a portion of the work and to move said work steadying elements toward but not into contact with the surface of the work, means responsive to the initial movement of the tool slide to actuate the means for producing feeding movement of the grinding wheel, and means for producing further sliding movement of the tool slide to advance said work steadying elements into engagement with the surface of the work as the work is engaged by the grinding wheel.

10. Apparatus as claimed in claim 9, wherein the movement of said work steadying elements effected by the further sliding movement of said tool slide is coordinated withthe feeding movement of the grinding wheel into the work so that said work steadying elements are maintained in engagement with the portion to be finished of the work as it is reduced in size by the grinding wheel.

References Cited by the Examiner UNITED STATES PATENTS 1,162,581 11/1915 Domizi 29-28 1,993,363 3/ 1935 Dreverholf 82-9 2,176,163 9/1939 Zimmerman 515 X 2,586,755 2/1952 Wilson 51-5 2,723,503 11/1955 Mader 51--105 LESTER M. SWVINGLE, Primary Examiner,

ROBERT C. RIORDON, Examiner, 

1. APPARATUS FOR FINISHING CRANKSHAFT BEARINGS AND THE LIKE COMPRISING FIRST MEANS FOR SKIVING A PREDETERMINED PORTION OF A BEARING, SECOND MEANS FOR GRINDING A PREDETERMINED DIFFERENT PORTION OF THE SAME BEARING, AND MEANS EFFECTIVE FIRST TO OPERATE SAID FIRST MEANS AND THEN TO OPERATE SAID SECOND MEANS. 